Issue #29079: Prevent infinite loop in pathlib.resolve() on Windows

2 files changed, 5 insertions, 1 deletions

diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index 69653938ef..0484dacd79 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -192,7 +192,9 @@ class _WindowsFlavour(_Flavour):
                         s = self._ext_to_normal(_getfinalpathname(s))
                     except FileNotFoundError:
                         previous_s = s
-                        s = os.path.abspath(os.path.join(s, os.pardir))
+                        s = os.path.dirname(s)
+                        if previous_s == s:
+                            return path
                     else:
                         if previous_s is None:
                             return s
diff --git a/Misc/NEWS b/Misc/NEWS
index 176b1e9e1c..1112257a28 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -40,6 +40,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #29079: Prevent infinite loop in pathlib.resolve() on Windows
+
 - Issue #13051: Fixed recursion errors in large or resized
   curses.textpad.Textbox.  Based on patch by Tycho Andersen.